Calciphylaxis is a potencially disorder in patients with hyperphosphatemic familial tumoral calcinosis (HFTC). Patients commonly present livedo racemosa and retiform purpura, which may progress to necrosis and very painful ulcers. Treatment with sodium thiosulfate provides good results; however, intralesional and intravenous treatment can be limited by its adverse effects. Topical sodium thiosulfate has been successfully reported for cutaneous calcification associated with connective tissue diseases and calciphylaxis in patients with chronic kidney disease. We provide a case report of a patient with HFTC and calciphylaxis who was treated with topical sodium thiosulfate with a rapid and complete response with no side effects.